Fetching Container Images with Podman to Creating a MySQL Database Instance

   
 podman  
 sysadmin  
Table of Content

Preface

getting started with podman

Scenario

  • Search for and fetch container images with Podman.
  • Run and configure containers locally.
  • Use the Red Hat Container Catalog.

Getting images

Podman users can use the search subcommand to find available images from remote or local registries. “podman search rhel“

Note:

This classroom’s Podman installation uses a several publicly available registries, like Quay.io and Red Hat Container Catalog.

After you have found an image, you can use Podman to download it. When using the pull subcommand, Podman fetches the image and saves it locally for future use:

[root@workstation student]# podman pull rhel
Trying to pull registry.access.redhat.com/rhel...
Getting image source signatures
Copying blob b77bb434db5a done
Copying blob 91592046c71b done
Copying config c61e4f9e8a done
Writing manifest to image destination
Storing signatures
c61e4f9e8adadac1824f46868b670f06f4a4c66f7043eaf4a68194af4d9097bc

[root@workstation student]# podman images
REPOSITORY                        TAG      IMAGE ID       CREATED       SIZE
registry.access.redhat.com/rhel   latest   c61e4f9e8ada   2 weeks ago   216 MB

Container images are named based on the following syntax:

registry_name/user_name/image_name:tag

e.g:

podman pull registry.access.redhat.com/rhel:latest

Running containers

The podman run command runs a container locally based on an image. At a minimum, the command requires the name of the image to execute in the container.

The container image specifies a process that starts inside the container known as the entry point. The podman run command uses all parameters after the image name as the entry point command for the container. The following example starts a container from a Red Hat Enterprise Linux image. It sets the entry point for this container to the echo “Hello world” command.

[root@workstation student]# sudo podman run ubi7/ubi:7.7 echo 'Hello!'
Trying to pull registry.access.redhat.com/ubi7/ubi:7.7...
Getting image source signatures
Copying blob fcd63ccfdd0c done
Copying blob 09dbbf8834d2 done
Copying config 0355cd652b done
Writing manifest to image destination
Storing signatures
Hello!

To start a container image as a background process, pass the -d option to the podman run command:

[student@workstation ~]$ sudo podman run -d rhscl/httpd-24-rhel7:2.4-36.8
009e9d587d603d6e123cd5044cd9fb8212669fee6f2a9d4c2feef5418370d0bc

And container just created and running

[root@workstation student]# podman container ls
CONTAINER ID  IMAGE                                                     COMMAND               CREATED        STATUS            PORTS  NAMES
009e9d587d60  registry.access.redhat.com/rhscl/httpd-24-rhel7:2.4-36.8  /usr/bin/run-http...  5 minutes ago  Up 5 minutes ago         gracious_hawking

And use inspect command to show ip of container

[root@workstation student]# podman inspect -l -f "{{.NetworkSettings.IPAddress}}" 
10.88.0.3

Open http://10.88.0.3:8080